Various implantable medical devices (IMDs) may be used for therapeutically treating or monitoring one or more physiological conditions of a patient. Such IMDs may be adapted to monitor or treat conditions or functions relating to heart, blood vessels, muscle, nerve, brain, stomach, endocrine organs or other organs and their related functions. Advances in design and manufacture of miniaturized IMDs have resulted in IMDs capable of therapeutic as well as diagnostic functions such as pacemakers, cardioverters, defibrillators, biochemical sensors, pressure sensors, various endovascular IMDs and the like. Such IMDs may have electronic functions and may be associated with electrical leads or may be wireless, with the ability to transmit data electronically either to another IMD implanted in the patient or to another device located externally of the patient, or both. Other IMDs may have purely mechanical and/or pharmaceutical functions, such as stents.
Although implantation of some IMDs requires a surgical procedure (e.g., pacemakers, defibrillators, etc.) other IMDs may be small enough to be delivered and placed at an intended deployment site in a relatively noninvasive manner, such as by a delivery catheter introduced percutaneously. Delivery also may be accomplished by advancing a catheter intravascularly through an exposed vasculature during a surgical procedure.